To reduce the risk and danger of being pierced by a needle head of a syringe accidentally and protect us by separating the needle head, a “safety syringe” as disclosed in R.O.C. Pat. No. M339311 adopts a combination of a sleeve and a telescopic tube, wherein a sliding groove is formed at the external periphery of the sleeve and a combining groove is concavely formed at the sleeve, and the telescopic tube comprises an elastic member, a sliding pipe with an embedding hole, and a pushing member, and the elastic member is configured to be corresponsive to the combining groove, and the sliding pipe is installed outside the sleeve, so that the tubes are sheathed and configured to be corresponsive to the elastic member, and a fixing member and a bump are provided to users to pull and rotate the telescopic tube to fix and hold the sleeve in order to protect the syringe body and preventing it from being exposed to the outside.
In addition, a “disposable safety syringe covering apparatus” as disclosed in R.O.C. Pat. No. 595482 comprises a cylindrical base unit and a sleeve unit, and the cylindrical base unit has a protrusion, and the sleeve unit has a T-shaped sliding groove, and the front end of the sleeve unit has an opening, wherein the cylindrical base unit is sheathed on an end of a needle to sheath the sleeve on the cylindrical base unit, so that the sleeve may slide back and forth along the longitudinal sliding groove, and the transverse sliding groove is fixed, so as to constitute a telescopic syringe covering apparatus.
The aforementioned two patented inventions are provided for protecting used needle heads to reduce the risk of being pierced by the needle head accidentally. Since these prior arts constitute various types of structures and apply the method of rotating the transverse sliding groove to fix the sleeve or cylindrical base unit, but they also increase the risk of loosening components. Therefore, the present invention provides another needle head structure of a safety syringe that improves the safety and secured connection of the needle head structure that are latched by a pulling and positioning method, so as to provide a more convenient use to medical professionals.